Objectives : 1. To determine SAPs gene expression in Candida albicans biofilm formed on acrylic surface in vitro, 2. To determine the effect of different protease inhibitors on C. albicans SAPs gene expression. Methods: The expression of SAP genes of C. albicans (ATCC 10231) with and without protease inhibitors saquinavir, ritonavir and indinavir was determined as follow: 2 μg of extracted RNA was reverse transcripted PCR was performed with primers from SAP1 to SAP 10 and EFB1. The condition for PCR was initial denaturation at 94°C for 5 min followed by 35 cycles at 94°C for 30 s, 52°C for 2 min and 72°C for 1 min and a final extension 72°C for 10 min. PCR products were analyzed by 1.5% agarose gel. The purified PCR products were quantified by the measurement of absorbance at 260 nm and 280 nm and used for the standard curve on real-time PCR reaction. The calculation of gene copy number on PCR product is based on 0.66μg for 1000bp DNA equal to 1ρmol and 1 mol equal to 6.023«1023 copies. SAP gene expression was normalized to the housekeeping gene EFB1. The experiments were performed in two separate occasions in duplicate. Results: SAP3 was not expressed in any of the samples. SAPs1,2,4,5,6 and SAP8 were expressed at low levels, SAP9 and SAP10 were expressed at relatively higher level while SAP7 was highly expressed, without the addition of protease inhibitors. Gene expressions were little affected by the addition of protease inhibitors except SAP7, which was consistently down-regulated by the protease inhibitors. Moreover, different protease inhibitors showed different degrees of inhibitions to SAP7 gene expression. Conclusions: SAP7 may play an important role in Candida biofilm heath and its expression can be altered differentially by different protease inhibitors.